Covishield is highly efficacious if two doses are given 12 weeks apart
On 1st of March, the second phase of COVID-19 vaccine rollout in India began on a positive note and millions of people took to getting themselves vaccinated. With more people eligible to take the vaccine jab, people surely breathed a sigh of relief, but a few doubts and confusion about the possible side-effects and the effectiveness of the vaccine still remain in the air.
That said, a recent study has claimed that the Oxford-Astrazeneca COVID vaccine known as Covishield in India, has proven to be 81.3% efficacious if the required two doses are given at an interval of 12 weeks.
Covishield vaccine: What you need to know
Covishield vaccine developed by the pharma giant AstraZeneca Inc. and Oxford University is being manufactured locally by the Serum Institute of India, the world's largest vaccine manufacturer.
The vaccine, when injected into a patient, triggers the immune system to produce antibodies that in turn fight COVID-19.
Covishield vaccine is administered in two doses given in the intervals of 4 to 12 weeks. It can survive at temperatures of 2 degrees C to 8 degrees C which is similar to a domestic refrigerator.
According to study
A recent study published in the Lancet journal established that Covishield is 81.3 per cent more effective when the two doses are administered 12 weeks apart.
The same study reported that the vaccine's efficacy was only 55.1 per cent when the two doses were administered between an interval of less than 6 weeks.
As per the study, people below the age of 55 develop a faster antibody response against the virus if the doses were taken 12 weeks apart.
According to the study, “Notably, in exploratory analyses, vaccine efficacy after a single standard dose was 76 per cent from Day 22 to Day 90, and antibody levels were maintained during this period with minimal waning.” “Overall, the value of this study is in providing evidence that a single dose of the Covishield vaccine is highly efficacious in the 90 days after vaccination, a longer prime-boost interval results in higher vaccine efficacy, and that protection against symptomatic Covid-19 is maintained despite a longer dosing interval,” the study adds.
Possible side-effects of Covishield vaccine
While Covishield is considered a safe vaccine to use, cases of side-effects and adverse reactions have arised in the recent past.
The factsheet associated with the Oxford-Astrazeneca vaccine lists pain, warmth, itching, bruising, fatigue, chills, fever, nausea, muscle ache, lumps and malaise as some of the common yet milder side-effects of the vaccine. While on the other hand, high fever, coughing, breathing difficulties, nervous problems, anaphylaxis have been categorized as some of the severe reactions of the vaccine.
Who should not get the Covishield jab?
While the eligibility criteria for the Covishield vaccine has expanded and while senior citizens above the age of 60 and select people over 45 years of age with comorbidities are now eligible for the COVID shot, some people must still refrain from getting the vaccine jab.
According to guidelines, if people have had allergic reactions in the past to certain foods/ ingredients which might be present in the Covishield dose, they are advised to avoid taking the vaccine.
People on blood thinning medications and those looking to conceive are also suggested to refrain from taking the vaccine. Additionally, patients who have recently had COVID-19 and are still being treated for the same are also asked to wait.